QLC（Quad-Level Cell） NAND flash will be one of the future technologies for next generation memory chip after three-dimensional（3D） TLC（Triple-Level Cell） stacked NAND flash. In QLC device, data errors will easil...QLC（Quad-Level Cell） NAND flash will be one of the future technologies for next generation memory chip after three-dimensional（3D） TLC（Triple-Level Cell） stacked NAND flash. In QLC device, data errors will easily occur because of 2~4 data levels in the limited voltage range. This paper studies QLC NAND technology which is 4 bits per cell. QLC programming methods based on 16 voltage levels and reading method based on ＂half-change＂ Gray coding are researched. Because of the probable error impact of QLC NAND cell＇s voltage change, the solution of generating the soft information after XOR（exclusive OR） the soft bits by internal read mechanism is presented for Low-Density Parity-Check（LDPC） Belief Propagation（BP） decoding in QLC design for its system level application.展开更多
针对煤矿松软破碎软岩巷道采用锚杆支护时锚固力普遍偏低、达不到设计要求的问题,开发了煤矿软岩钻孔顶部扩孔钻头,并分别在实验室和煤矿井下现场进行了扩孔效果和扩孔锚固性能对比试验。试验结果表明:新研制的扩孔钻头在扩孔段扩孔直...针对煤矿松软破碎软岩巷道采用锚杆支护时锚固力普遍偏低、达不到设计要求的问题,开发了煤矿软岩钻孔顶部扩孔钻头,并分别在实验室和煤矿井下现场进行了扩孔效果和扩孔锚固性能对比试验。试验结果表明:新研制的扩孔钻头在扩孔段扩孔直径比普通钻孔直径大5.3 mm左右,煤矿井下100 mm短锚固拉拔对比试验时,扩孔钻孔锚杆最大锚固力达112.3 k N,为普通钻孔锚固力的1.55倍。并且在树脂锚固剂和钻孔煤岩壁之间发生脱锚后,良好的机械摩擦阻力使锚杆锚固力一直保持基本不变,充分反映了软岩扩孔锚固的良好效果。展开更多
文摘QLC（Quad-Level Cell） NAND flash will be one of the future technologies for next generation memory chip after three-dimensional（3D） TLC（Triple-Level Cell） stacked NAND flash. In QLC device, data errors will easily occur because of 2~4 data levels in the limited voltage range. This paper studies QLC NAND technology which is 4 bits per cell. QLC programming methods based on 16 voltage levels and reading method based on ＂half-change＂ Gray coding are researched. Because of the probable error impact of QLC NAND cell＇s voltage change, the solution of generating the soft information after XOR（exclusive OR） the soft bits by internal read mechanism is presented for Low-Density Parity-Check（LDPC） Belief Propagation（BP） decoding in QLC design for its system level application.
文摘针对煤矿松软破碎软岩巷道采用锚杆支护时锚固力普遍偏低、达不到设计要求的问题,开发了煤矿软岩钻孔顶部扩孔钻头,并分别在实验室和煤矿井下现场进行了扩孔效果和扩孔锚固性能对比试验。试验结果表明:新研制的扩孔钻头在扩孔段扩孔直径比普通钻孔直径大5.3 mm左右,煤矿井下100 mm短锚固拉拔对比试验时,扩孔钻孔锚杆最大锚固力达112.3 k N,为普通钻孔锚固力的1.55倍。并且在树脂锚固剂和钻孔煤岩壁之间发生脱锚后,良好的机械摩擦阻力使锚杆锚固力一直保持基本不变,充分反映了软岩扩孔锚固的良好效果。
